Implant method for securing artificial teeth

ABSTRACT

A SELF-DRILLING IMPLANT ADAPTED TO BE DRILLED INTO THE ROOT OF A TOOTH THROUGH AN END OF A REDUCED DIAMETER WHILE ITS OUTER END IS BENT TO FORM A HEAD OVER WHICH IS FITTED AN ARTIFICIAL TOOTH. THE IMPLANT IS MADE OF A METAL SUCH AS STEEL THE VICKERS HARDNESS OF WHICH RANGES BETWEEN 300 AND 500 AND IS PREFERABLY EQUAL TO ABOVE 350.

March 2, 1971 J, SC 3,566,470

IMPLANT METHOD FOR SECURING ARTIFCIAL TEETH v Filed Feb. 16. 1968 I 7l/mar" United States Patent 3,566,470 llVIPLANT METHOD FOR SECURINGARTIFICIAL TEETH Jacques Scialom, 15 Ave. Francis Berthier, 94 Le ParcSaint-Maur, France Continuation-impart of application Ser. No. 253,113,Jan. 22, 1963. This application Feb. 16, 1968, Ser. No. 705,974 Claimspriority, application France, Feb. 20, 1967,

3 The portion of the term of the patent subsequent to June 4, 1985, hasbeen disclaimed Int. Cl. A61c 13/00 US. Cl. 32-10 1 Claim ABSTRACT OFTHE DISCLOSURE A self-drilling implant adapted to be drilled into theroot of a tooth through an end of a reduced diameter while its outer endis bent to form a head over which is fitted an artificial tooth. Theimplant is made of a metal such as steel the Vickers hardness of whichranges between 300 and 500 and is preferably equal to above 350.

The term self-drilling implan as used throughout the specification andthe claims is to be understood as an implant provided at one of its endswith a cutting section such that the implant may be used to drill a holein which it is to be lodged.

In my copending application Ser. No. 253,113, now Pat. No. 3,386,169,filed on Jan. 22, 1963 and entitled Method and Means for Attaching Teethand the Like to the Maxillar Bone, of which the present application is acontinuation-in-part, I have described a method for securing dentalprostheses to the bone of the maxillary by means of self-drillingimplants provided at one of their ends with a cutting edge and at theirother end with a head adapted to be driven by any suitable mechanicalmeans. The results obtained by means of such implants driven into thebone tissue have been extremely favorable since a number of very specialconditions were simultaneously satisfied thereby: on the one hand theengagement inside the bone tissue becomes a very easy matter by reasonof the reduced hardness and large elasticity of the latter and on theother hand, the implant is reliably and securely held in position byreason of this same elasticity and of the speedy osteosynthesis whichclamps tightly the implant inside its housing and lastly the metalforming the implant is tantalum which is non-attacked by the liquidscarried by the bone tissue and also is bestowed with the metallurgicalproperties required for executing a drill therewith.

However, the insertion of such drills into the actual tooth appeared tobe impossible for difierent reasons. Firstly, the material forming thetooth or so-called dentine is neither soft nor elastic but is hard andonly very slightly elastic. Under such conditions, it seemed highlyimprobable that a self-drilling implant of the type to be inserted intothe bone tissue could be inserted through a self-drilling operation intodentine and be clamped tightly by the dentine when inserted thereinwithout any further operation being required. Furthermore, an obliqueinsertion is not applicable in the case of the actual tooth, except inrare instances and no one could imagine it might be possible to obtain areliable securing of the implant without a preliminary drilling of acavity and without sealing the implant in such a cavity by means ofcement as is the case of a conventional securing of a pivot into atooth. Nor could any one imagine that it might be possible to resort toa metal other than tantalum for the 3,566,470 Patented Mar. 2, 1971 "iceexecution of the implant and in particular to certain metals generallyused by dentists, with which metals it might be possible to obtaintogether a sufficient sharpening for the implant to enter the tooth, anelasticity such as to cut out any risk of breaking during the drillingoperation, since such a breaking would be a most serious mishap and aductility high enough to allow the outer section of the implantincluding the head to be bent if required at a suitable angle, since theimplant has been inserted in the root of a tooth, the artificial toothbeing fitted over such a bent head.

My investigations have led me to perfect a method for securing anartificial tooth to the actual dentine of the root of a tooth and todevise a novel implant for the execution of said method.

I will now describe by way of example, reference being made to thesingle figure of the accompanying drawing, an implant executed inaccordance with my invention and I will also disclose the method forsecuring an artificial tooth to the root of a tooth in accordance withmy invention.

As illustrated, the implant is constituted by a substantiallycylindrical stem or rod 6 of a circular or polygonal outline thediameter of which ranges between 0.3 and 1.5 mm. and preferably between1 and 1.2 mm. One of its ends is defined by cutting edges 5 formed inthe case illustrated at the end of a flattened section 3.

The section of the implant provided with cutting edges has a breadthless than or at the utmost equal to the diameter of the rod 6 formingthe implant. Under such conditions, the diameter of the hole to bedrilled in the root of the tooth is slightly less than or at the utmostequal to that of said rod, and consequently when the implant isaccurately positioned, the self-drilling implant is tightly held insidethe housing drilled by it.

At its other end, the rod 6 carries a head 7 which is not cylindricaland which serves for driving the rod into rotation, the shape of saidhead being such that it can be fitted in conventional rotary drivingmeans such as the socalled contra-angles.

The implant is made of a metal such as steel for instance showing thefollowing properties:

A hardness suflicient for its cutting edges to be capable of drillinginside the tooth dentine, said hardness ranging between 300 and 500Vickers, preferably above 350 Vickers. However, it should not be brittlein its section 8 adjacent the head so that the operator, after urgingthe instrument into position, may deform it without risking a breakingor splitting of the tooth.

The artificial tooth is secured as follows in accordance with myinvention:

The root of the tooth being prepared in the usual manner after removingthe nerve out of the dental canal 1, 2, the self-drilling implant isfitted in a contra-angle or the like conventional rotary driving means.The implant is then caused to rotate under the action of thecontra-angle and urged into the dental canal as provided by a graduallyincreasing pressure applied to it. Since the cutting edge of the implantdrills a hole the diameter of which is not larger than that of the rod6, at least part of the pulverulent dentine produced in the drillingremains in the gap between the outer surface of the implant rod and theinner surface of the hole which is being drilled and is highlycompressed inside said gap, which ensures, taking into account the lowelasticity of the dentine, carrying no cement, an excellent locking ofthe implant in position. The implant may extend up to the apex of theroot and if the dental canal is incurved it continues progressing alonga straight line as illustrated.

When the implant has been sufliciently driven into the root the operatorremoves the contra-angle and leaves the implant in position inside theroot. He bends the'outwardly projecting end 8 of the implant so as togive it any suitable shape such as that of a hook, as illustrated. It isthen an easy matter to secure the artificial tooth 10 over the head 7, 8of the implant with the interposition of a false stump 9, as provided byconventional means.

Instead of inserting the implant into the dental canal, it may beinserted inside the solid section of the tooth. In the latter case, itis of advantage to resort to self-drilling implants of the typedisclosed the diameter of which is very small and ranges between 0.3 and0.8 mm. a preferred value being 0.5 mm. whilethe length of its rodsection is small, its total length ranging between 4 and 10 mm. and anumber of such implants being distributed within the periphery of theroot.

It should be remarked that self-drilling implants thus inserted into atooth cannot practically be torn out since they have been inserted witha force fit into a hole drilled by the implant itself and the diameterof which is less than or at the utmost equal to that of the implant rod.

What I'claim" is 1. A method for securing an artificial tooth on theroot of a patients tooth consisting in engaging with a rotaryinstrumentality an implant provided at one end with a terminal cuttingsection of a diameter less "than the remainder of the implant,introducing during its rotation said implant without any cement into theroot down to a predetermined depth, removing the rotary instrumentality,bending the other end of the implant which is opposite said one end andwhich projects outwardly of the root, and fitting an artificial toothover said other end.

References Cited UNITED STATES PATENTS 3,386,169 6/1968 Scialo m' 32-10403,428 5/1889 Hansen 3213 616,302 12/1898 'Evans 32-13 2,472,103 6/1949Giesen '12892E ROBERT PESHOCK, Primary Examiner

